Universal machine tool

ABSTRACT

A universal machine tool having a workpiece slide movable on a machine bed by means of a motor for the workpieces to be machined and a machining unit which is movable about a plurality of axes by means of a motor. The machining unit includes a motor-driven work spindle for receiving the machining tools. To enable turning operations in addition to milling and drilling operations with high cutting performance in a single clamping position, according to the present invention, the workpiece slide is provided with at least one rotatable workpiece accommodation and an associated rotary drive means. The rotary drive means can drive the workpiece accommodation for carrying out turning operations on the workpiece to be machined.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to a universal machinetool and more specifically to a universal machine tool having amachining unit and a workpiece slide. The machining unit is movablealong a plurality of axes by means of a motor and includes amotor-driven work spindle for receiving the machining tools. Theworkpiece slide is for the workpieces that are to be machined and ismovable on a machine bed by means of a motor.

[0003] 2. Discussion of the Prior Art

[0004] In a conventional universal milling, drilling, and boringmachine, such as that disclosed in European Patent 0 664 176, the workspindle is carried by a swiveling milling head which is turnable about alocating face that is inclined by 45 degrees with respect to thevertical plane. The milling head is located on a vertical face wall of asupport housing. The support housing is attached to the face of atravelling stand so as to be vertically movable. The travelling stand ismounted on guiding rails in the rear end of a machine bed so as to bemovable by means of a motor. On the front part of the machine bed, atable slide having a workpiece table is located so as to be horizontallymovable. With such an arrangement for the machine tool, complex milling,drilling, and threading operations may be carried out on a plurality ofsides of a workpiece, in a single clamping position. However, no turningoperations can be carried out with such a machine. This includes arotary main cutting motion by the workpiece.

[0005] Conventional turning machines having tool revolvers into whichsmaller boring or milling heads may be inserted are well known. Inthese, however, the moving capabilities and the cutting performance ofthe milling heads are limited and driving these machines is relativelycomplicated. The range of applications of such milling and drillingheads in turning machines is therefore limited.

[0006] One would prefer a universal machine tool which, in addition tomilling and drilling operations with high cutting performance, alsoenables turning operations for a complete automatic machining ofworkpieces in one clamping position.

SUMMARY OF THE INVENTION

[0007] According to the present invention, a workpiece slide isdisclosed with at least one turnable workpiece accommodation and anassociated rotary drive by which the workpiece accommodation can bedriven for carrying out turning operations on the workpiece to beprocessed.

[0008] The universal machine tool according to the present inventionprovides the possibility to carry out turning operations by means of arotary main cutting motion by the workpiece, in addition to milling,drilling, and threading operations by means of a rotary main cuttingmotion by the tool. In this way, an effective, automatic completemachining of workpieces of even complicated shapes may be effectedwithout any complicated re-clamping of the workpieces between a turningand a milling or drilling machine. By avoiding the re-clamping of theworkpieces, a higher machining accuracy is obtainable. Another importantadvantage of the machine tool of the present invention is that thetravelling paths of a work spindle provided for milling and drilling mayalso be used for the feeding and supply motions for turning operations,whereby the complexity of the construction and control technology may bedecreased. Aside from the milling technology, the turning technology mayalso be covered by one control with the same user interface.

[0009] The workpiece accommodation may, for example, be formed as ahorizontal rotary spindle including workpiece clamping means. In aparticularly robust and stiff embodiment, the rotary spindle is, forexample, borne in a spindle head integrally formed with the workpieceslide. The rotary spindle may, however, also be disposed in a separatespindle head which can be mounted on a workpiece slide if required. Thearrangement enables a simple retrofit or detachment of the rotaryspindle for possibly changing machining tasks.

[0010] In addition to or instead of the horizontal rotary spindle, theworkpiece slide may also include a horizontal workpiece table which isturnable about a vertical axis and includes an integrated rotary driveas a workpiece accommodation. With a machine tool having such aworkpiece slide, milling and turning operations can be carried out inone clamping position even on larger or bulky workpieces. Thus, therange of applications of the machine tool can be widened, and machiningaccuracy may be enhanced.

[0011] The workpiece accommodation may, for example, be driven by aring-shaped driving motor comprising a stator ring fixed, for example,to a console of the workpiece slide and a rotor ring fixed to theturntable resulting in a particularly compact embodiment. The drivingmotor may, for example, be a collectorless ring-shaped torque motorenabling a direct drive with high dynamics and exact positioning withoutan additional gearing or coupling. The workpiece accommodation may, withsuch little spatial requirements and weight, not only be driven withhigh dynamics for carrying out turning operations, but may also bepositioned in arbitrary angular positions to carry out, for example,special milling or drilling operations.

[0012] In another preferred embodiment of the present invention, aworkpiece exchanger that can be inserted into the work spindle isprovided. Since the work spindle can carry out all of the movementsrequired for a workpiece exchange at the rotary spindle, no separatedriving motors or travelling elements are necessary in this case. Theworkpiece exchanger may, for example, be a workpiece gripper providedwith a plurality of gripper arms by which the finished workpieces aretransported from the rotary spindle to a workpiece deposit. The rotaryspindle may also be supplied with new workpieces via the workpiecegripper. A rod feeding magazine may also be provided by which theturning spindle is supplied with rod-shaped material.

[0013] In a simple and effective embodiment, the workpiece gripper mayoperate via an internal coolant supply in the work spindle. This way,additional operational components may be omitted.

[0014] Also, an automatically operable three or more jaw chuck may belocated on the rotary spindle. The rotary spindle, however, may alsohave an internal clamping cone for receiving different power jaw chucks.

BRIEF DESCRIPTION OF THE DRAWING

[0015] The above and other objects and advantages of the presentinvention will be more readily appreciated from the following detaileddescription when read in conjunction with the accompanying drawing,wherein:

[0016]FIG. 1 is a perspective side view of a universal machine tool formilling, drilling, and turning operations according to the presentinvention;

[0017]FIG. 2 is a perspective, partially cross sectional side view ofthe universal machine tool of FIG. 1 including a rod feeding magazineand a protective cabin;

[0018]FIG. 3 is a partially cross sectional perspective view of analternative workpiece slide comprising a turntable; and

[0019]FIG. 4 is a perspective view of the workpiece slide of FIG. 3including a clamped workpiece and turning tools for explanation of theturning operations in the universal machine tool according to thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The universal machine tool shown in FIG. 1 includes a machine bed1 on which a workpiece slide 2 is disposed so as to be movable along ay-axis in the direction of the double arrow 3 by means of a motor (notshown). The workpiece slide includes a spindle head 4 which bears ahorizontal rotary spindle 5 which is driven by means of a driving motor(not shown). The rotary spindle is provided with an automaticallyoperable three jaw chuck 6 as a means for clamping workpieces. Therotary spindle may, however, also be provided with other workpiececlamping means and/or an internal clamping cone for receiving differentpower jaw chucks or the like.

[0021] On the rear part of the machine bed 1 are mounted guiding rails 7and 8 on which a travelling stand 9 is guided so as to be horizontallymovable along an x-axis via a motor-driven threaded spindle 10. On thefront side of the travelling stand is a support housing 11 that isvertically movable up and down along a z-axis in the direction of thedouble arrow 12. The support housing has a face wall 13 that is inclinedby 45 degrees with respect to the vertical plane and extending obliquelydownward. Mounted on the face wall is a swiveling milling head 14including a work spindle 15 turnable by means of a motor (not shown).The milling head and work spindle form a machining unit that is turnableabout a swiveling axis 16 which is perpendicular to the face wall. Thework spindle is borne within the swiveling milling head in an angle of45 degrees with respect to the swiveling axis. By a correspondingrotation of the swiveling milling head about the swiveling axis, thework spindle can thus be turned from a vertical machining positionindicated by solid lines to a horizontal machining position indicated bybroken lines. At the end of the machine bed a chip conveyer 17 islocated for removing the chips produced during the machining process.

[0022] Aside from the tools for milling, drilling, boring, or threadingoperations, for example, the tools for turning operations may also beinserted into the work spindle 15. The tools may be disposed incorresponding clamps or tool accommodations which are deposited in atool magazine (not shown) and can be inserted into the work spindle bymeans of an appropriate tool exchanger (not shown). For carrying outturning operations on a workpiece clamped to the rotary spindle 5, atool carrier for indexable inserts can be inserted into the workspindle. The rotary main cutting motion is then generated by themotor-driven rotary spindle. The feeding motion along the y-axis iscreated by moving the workpiece slide 2 with the rotary spindle arrangedthereon while the feeding motions along the x- and z-axes are created bymoving the travelling stand 9 and the support housing 11. Also complexturning motions may be carried out with high precision by a controlledmovement along the individual travelling and turning axes. Furthermore,the common tools for milling, drilling, boring, and threading processesor the like can also be inserted into the work spindle. Therefore, allother types of machining, such as milling, drilling, boring, reaming,and threading can also be carried out on the workpieces clamped to theturning spindle before or after the turning operations. Thus, completemachining without any complicated re-clamping between different types ofmachines is enabled.

[0023] A workpiece exchanger 18 shown in FIG. 1 for exchanging theworkpieces clamped to the rotary spindle 5 may also be insertable intothe work spindle 15. The insertion of the workpiece exchanger into thework spindle may be performed by an automatic tool exchanger (notshown). The workpiece exchanger is deposited in a tool magazine (alsonot shown) during the machining process. The workpiece exchanger may,for example, be a workpiece gripper provided with a plurality ofgripping arms 19 insertable into the work spindle via a clamping cone.The gripping arms may be operated by the internal coolant supply of thework spindle in an efficient embodiment. Since a relatively highpressure of 40 bar, for example, is generally available via the coolantsupply of the machine tool, then no additional power supply is requiredfor the operation of the gripping arms 19. With the workpiece exchanger18 movable by means of the work spindle, the finished workpieces can bedetached from the rotary spindle and transported to a workpiece deposit(not shown). The rotary spindle may also be supplied with new workpiecesvia the workpiece exchanger.

[0024] In the further embodiment of the universal machine tool accordingto the present invention shown in FIG. 2, a well known rod feedingmagazine 35 is located in front of the machine bed 1. With this rodmagazine, rod shaped workpieces may be transported to the rotary spindle5 formed as a hollow shaft and clamped by the three jaw chuck 6. In FIG.2, a protective cabin 36, used to enclose the machine tool, is shown aswell.

[0025] In FIG. 3, another workpiece slide 20 is shown which can be usedinstead of the workpiece slide 2 illustrated in FIGS. 1 and 2. Thisworkpiece slide 20 comprises a console 21 on which a horizontalturntable 22 is borne via a ring bearing 23 so as to be rotatable abouta vertical axis. In a ring space 24, vertical to the rotational axis ofthe turntable within the console, is located a driving motor 25. Thedriving motor includes an inner stator ring 26 fixedly connected to theconsole on the inner wall of the ring space and an outer rotor ring 27fixed to the bottom side of the turntable. On the bottom side of theturntable and concentric to its rotational axis is a tappet 28protruding downward. About the tappet is arranged a slip ring 29 and ashaft encoder 30. For example, the driving motor may be a collectorlessring-shaped torque motor enabling, in addition to high dynamics forcarrying out turning operations, an exact positioning for carrying outmilling and drilling operations in different angular positions evenwithout a coupling or gearing.

[0026] Clamping by the turntable 22 of FIG. 3 or the rotary spindle 5 ofFIG. 1, for carrying out a milling process on a workpiece which is notrotationally driven, may be accomplished by the motor or a separateclamping means which can be activated if required. In addition, one ormore flyweight sensors, by which an unacceptable flyweight can bedetected and by which the machine tool can be turned off, may bedisposed on the turntable or the rotary spindle.

[0027]FIG. 4 shows an embodiment for turning operations in a machinetool according to the present invention including the workpiece slide 20according to FIG. 3. On the turntable 22, a table 31 to be machined isclamped upside down. With the aid of turning tools 32, 33, and 34 whichcan be inserted into the work spindle 15 shown in FIG. 1, differentturning operations may be carried out with a corresponding drive of theturntable. For example, turning operations on the inner and outer sideof the turntable may be carried out with the turning tools 32 and 34,and recessing works may be effected by the turning tool 33. Many otherturning operations will be known to one of ordinary skill in the art.

[0028] The invention is not limited to the embodiments described indetail and shown in the drawings. The turning spindle may, for example,be disposed in a separate spindle head which is, for example, detachablymounted on a table slide. The workpiece slide may additionally comprisea rotary spindle turnable about a horizontal axis as well as a workpiecetable turnable about a vertical axis.

[0029] While the invention has been illustrated and described by meansof specific embodiments, it is to be understood that numerous changesand modifications may be made therein without departing from the spiritand scope of the invention as defined in the appended claims andequivalents thereof.

What is claimed is:
 1. A universal machine tool comprising: a machiningunit movable about a plurality of axes by means of a motor andcomprising a motor-driven work spindle for receiving the machiningtools; and a workpiece slide for the workpieces to be machined which ismovable on a machine bed by means of a motor and comprises at least onerotatable workpiece accommodation and an associated rotary drive bywhich the workpiece accommodation can be driven for carrying out turningoperations on the workpiece to be machined.
 2. The universal machinetool as defined in claim 1, wherein the workpiece accommodation isarranged so as to be turnable about a vertical or horizontal axis. 3.The universal machine tool as defined in claim 1, wherein the workpieceaccommodation is formed as a rotary spindle including a clampingarrangement.
 4. The universal machine tool as defined in claim 3,wherein the clamping arrangement comprises an automatically operablethree jaw chuck.
 5. The universal machine tool as defined in claim 3,wherein the clamping arrangement comprises an inner clamping cone asclamping means.
 6. The universal machine tool as defined in claim 3,further comprising a rod feeding magazine that is allocated to therotary spindle.
 7. The universal machine tool as defined in claim 1,wherein the workpiece accommodation is formed as a horizontal turntable.8. The universal machine tool as defined in claim 1, wherein the rotarydrive is a ring-shaped driving motor comprising a stator ring fixed to aconsole of the workpiece slide and a rotor ring fixed to the workpieceaccommodation.
 9. The universal machine tool as defined in claim 8,wherein the driving motor is a collectorless torque motor.
 10. Theuniversal machine tool as defined in claim 1, further comprising aworkpiece exchanger for supplying workpieces to the workpieceaccommodation, for removing the workpieces, or for both, wherein theworkpiece exchanger is insertable into the work spindle.
 11. Theuniversal machine tool as defined in claim 10, wherein the workpieceexchanger is a workpiece gripper provided with a plurality of grippingarms.
 12. The universal machine tool as defined in claim 10, wherein theworkpiece exchanger is operable by means of an internal coolant supplyof the work spindle.